Add the oil to a large skillet set over high heat. Pat the roast dry with paper towels. Sear the roast on all sides, using tongs to turn, until done. Once fully seared transfer the roast to the bowl of a slow cooker.
3 tbsp extra virgin olive oil, 4 lb chuck roast
To the pot you seared the roast in reduce the heat to medium, then add the onion and cook just until translucent, stirring often.
1/2 yellow onion
Add the garlic, tomato paste, brown sugar, Italian seasoning, garlic powder, onion powder, and chili powder. Stir often.
6 cloves garlic, 2 tbsp tomato paste, 2 tsp brown sugar, 2 tsp Italian seasoning, 1 tsp garlic powder, 1 tsp onion powder
Add the Worcestershire sauce and a bit of the beef broth to the pot, then use a sturdy spoon to deglaze the pan and scrape any browned bits of flavor off of the bottom.
2 tsp Worcestershire sauce, 32 oz beef broth
Add the garlic, potatoes, and carrot mixture to the bowl of a slow cooker. Add the rest of the beef broth, fresh herbs, and the bay leaves pushing them down into the liquid.
1 1/2 lbs baby carrots, 2 lbs baby gold potatoes, 4 sprigs fresh rosemary, 4 sprigs fresh thyme, 2 bay leaves, salt & pepper
Cover and cook on LOW for 8-10 hours, or HIGH for 5-6, until the roast's perfectly tender and easily shreds. Transfer the roast to a waiting cutting board or serving platter.
Pour the leftover liquid in the crockpot through a strainer into a sauce pan on the stove set over medium heat. Add the cornstarch and cold water to a small prep bowl, then whisk together until evenly combined. Stir the slurry into the pot roast juices.
3 tbsp cornstarch
Bring the mixture to a simmer and cook, stirring often, until the gravy's thickened some.
Serve the roast and vegetables warm with gravy.